U.S. patent application number 10/168137 was filed with the patent office on 2003-02-06 for optically active materials.
Invention is credited to Cherkaoui, Zoubair Mohammed, Schmitt, Klaus.
Application Number | 20030028048 10/168137 |
Document ID | / |
Family ID | 26153628 |
Filed Date | 2003-02-06 |
United States Patent
Application |
20030028048 |
Kind Code |
A1 |
Cherkaoui, Zoubair Mohammed ;
et al. |
February 6, 2003 |
Optically active materials
Abstract
A compound is of formula (I), in which: A.sup.1 to A.sup.4,
E.sup.1 and E.sup.2 each independently represent hydrogen or an
optionally-substituted hydrocarbon group; B.sup.1 and B.sup.2 each
independently represent a single bond, an oxygen atom or an
optionally-substituted hydrocarbon group; MG.sup.1 and MG.sup.2
each independently represent an optionally-substituted ring system;
CG is a divalent or polyvalent chiral group. The optically active
compound may be used as a doping agent for liquid crystals for a
wide range of applications including solid state cholesteric
filters for projection displays, circular polarisers, optical
filters, etc.
Inventors: |
Cherkaoui, Zoubair Mohammed;
(Allscwil, CH) ; Schmitt, Klaus; (Lorrach,
DE) |
Correspondence
Address: |
Finnegan Henderson Farabow Garrett & Dunner
1300 I Street N W
Washington
DC
20005-3315
US
|
Family ID: |
26153628 |
Appl. No.: |
10/168137 |
Filed: |
June 20, 2002 |
PCT Filed: |
December 20, 2000 |
PCT NO: |
PCT/CH00/00673 |
Current U.S.
Class: |
560/66 |
Current CPC
Class: |
C09K 19/2028 20130101;
C09K 2019/0448 20130101; C09K 19/586 20130101; C09K 2323/00
20200801; C09K 19/2014 20130101 |
Class at
Publication: |
560/66 |
International
Class: |
C07C 069/92 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 1999 |
EP |
99310561.8 |
Dec 23, 1999 |
GB |
9930557.5 |
Claims
1. A compound of formula I: 15in which: A.sup.1 to A.sup.4 each
independently represent hydrogen; an optionally-substituted methyl
group; or an optionally-substituted hydrocarbon group of 2 to 80
C-atoms, in which one or more C-atoms may be replaced by a
heteroatom, in such a way that oxygen atoms are not linked to one
another; E.sup.1 and E.sup.2 each independently represent hydrogen;
an optionally-substituted methyl group; or an
optionally-substituted hydrocarbon group of 2 to 80 C-atoms, in
which one or more C-atoms may be replaced by a heteroatom, in such
a way that oxygen atoms are not linked to one another; B.sup.1 and
B.sup.2 each independently represent a single bond, an oxygen atom
or an optionally-substituted hydrocarbon group of 1 to 80 C-atoms.
in which one or more C-atoms may be replaced by a heteroatom, in
such a way that oxygen atoms are not linked to one another;
MG.sup.1 and MG.sup.2 each independently represent an
optionally-substituted aromatic or non-aromatic carbocyclic or
heterocyclic ring system, with 1 to 80 C-atoms; CG is a divalent or
polyvalent chiral group; and n1 and n2 are each independently 1 or
2, where "n1=2" (or "n2=2") indicates the presence of two separate
linkages via the groups B.sup.1 (or the groups B.sup.2) between the
groups MG.sup.1 and CG (or CG and MG.sup.2); and in which further
the substructures A.sup.1-MG.sup.1-A.sup.2 and
A.sup.3-MG.sup.2-A.sup.4 each have a longitudinal axis and are
linked lateral to the said longitudinal axis to B.sup.1 and
B.sup.2, respectively.
2. A compound as claimed in claim 1, in which CG is a chiral group
derived from a sugar, from an optically active biaryl group, or
from a bifunctional or polyfunctional compound comprising an
optically active alcohol, glycol or amino acid.
3. A compound as claimed in claim 1 or 2 in which: n1=n2=1
4. A compound as claimed in any preceding claim, in which at least
one of A.sup.1 to A.sup.4, E.sup.1 and E.sup.2 includes a
polymerisable group.
5. A compound as claimed in claim 4, in which at least one of
A.sup.1 to A.sup.4, E.sup.1 and E.sup.2 independently is selected
from formula (II): P-(Sp.sup.1).sub.k1-(X.sup.1).sub.t1- (II)
wherein: P is hydrogen or a polymerisable group selected from
groups comprising CH.sub.2.dbd.CW--, CH.sub.2.dbd.CW--O--,
CH.sub.2.dbd.CW--COO--, CH.sub.2.dbd.C(Ph)--COO--,
CH.sub.2.dbd.CH--COO--Ph--, CH.sub.2.dbd.CW--CO--NH--,
CH.sub.2.dbd.C(Ph)--CONH--, CH.sub.2.dbd.C(COOR')--CH.sub.2--COO--,
CH.sub.2.dbd.CH--O--, CH.sub.2.dbd.CH--OOC--, (Ph)--CH.dbd.CH--,
CH.sub.3--C.dbd.N--(CH.sub.2).sub.m3--, HO--, HS--,
HO--(CH.sub.2).sub.m3--, HS--(CH.sub.2).sub.m3--,
HO(CH.sub.2).sub.m3COO-- -, HS(CH.sub.2).sub.m3COO--, HWN--,
HOC(O)--, CH.sub.2.dbd.CH--Ph--(O).sub- .m4. 16wherein: W
represents H, F, Cl, Br or I or a C.sub.1-5 alkyl group; m3 is an
integer having, a value of from 1 to 9; m4 is an integer having a
value of 0 or 1, R' represents a C.sub.1-5 alkyl group; and R"
represents a C.sub.1-5 alkyl group, methoxy, cyano, F, Cl, Br or I;
Sp.sup.1 represents an optionally-substituted C.sub.1-20 alkylene
group, in which one or more C-atoms may be replaced by a
heteroatom; k.sup.1 is an integer having a value of from 0 to 4;
X.sup.1 represents --O--, --S--, --NH--, N(CH.sub.3)--, --CH(OH)--,
--CO--, --CH.sub.2(CO)--, --SO--, --CH.sub.2(SO)--, --SO.sub.2--,
--CH.sub.2(SO.sub.2)--, --COO--, --OCO--, --OCO--O--, --S--CO--,
--CO--S--, --SOO--, --OSO--, --SOS--, --CH--CH.sub.2--,
--OCH.sub.2--, --CH.sub.2O--, --CH.dbd.CH--, or --C.ident.C--; and
t.sup.1 is an integer having a value of 0 or 1; wherein the term Ph
denotes phenylene and (Ph) denotes phenyl.
6. A compound as claimed in claim 5, in which one or more of
CH.sub.2 groups present in the hydrocarbon chain of an the
optionally-substituted C.sub.1-20 alkylene group Sp.sup.1 is
replaced, independently, by one or more groups selected from --O--,
--S--, --NH--, N(CH.sub.3)--, --CH(OH)--, --CO--, --CH.sub.2(CO)--,
--SO--, --CH.sub.2(SO)--, --SO.sub.2--, --CH.sub.2(SO.sub.2)--,
--COO--, --OCO--, --OCO--O--, --S--CO--, --CO--S--, --SOO--,
--OSO--, --SOS--, --C.ident.C--, --(CF.sub.2)-.sub.r,
--(CD.sub.2).sub.s-- or C(W.sup.1).dbd.C(W.sup.2)--, with the
proviso that no two oxygen atoms are directly linked to each other,
wherein W.sup.1 and W.sup.2 each represent, independently, H,
H--(CH.sub.2).sub.q1-- or Cl and the integers r, s and q1 each
independently represent a number of between 1 and 15.
7. A compound as claimed in any preceding claim, in which A.sup.1
to A.sup.4 and E.sup.1 to E.sup.2 each independently represent a
group of formula (III): P.sup.2-Sp.sup.5-X.sup.4- (III) wherein:
P.sup.2 represents hydrogen, CH.sub.2.dbd.CW.sup.5-- or
CH.sub.2.dbd.CW.sup.5--(C- O).sub.v2O--, 17wherein: W.sup.5
represents H, CH.sub.3, F, Cl, Br or I; and v2 is 0 or 1, R'
represents a C.sub.1-5 alkyl group; and R" represents a C.sub.1-5
alkyl group, methoxy, cyano, F, Cl, Br or I; Sp.sup.5 represents a
C.sub.1-20 straight-chain alkylene group, especially ethylene,
propylene, butylene, pentylene, hexylene, heptylene, octylene,
nonylene, decylene, undecylene, or dodecylene; and X.sup.4
represents --O--, --CO--, --COO--, --OCO--, --C.ident.C--, or a
single bond, especially --O--, --COO--, --OCO-- or single bond.
8. A compound as claimed in any preceding claim, in which each or
either of the groups B.sup.1 and/or B.sup.2 comprises a group of
formula (IV): (X.sup.2).sub.t2-(Sp.sup.2).sub.k2-(X.sup.3).sub.t3
(IV) wherein: Sp.sup.2 represents a C.sub.1-20 alkylene group;
X.sup.2 and X.sup.3 each independently represent --O--, --S--,
--NH--, N(CH.sub.3)--, --CH(OH)--, --CO--, --CH.sub.2(CO)--,
--SO--, --CH.sub.2(SO)--, --SO.sub.2--, --CH.sub.2(SO.sub.2)--,
--COO--, --OCO--, --OCO--O--, --S--CO--, --CO--S--, --SOO--,
--OSO--, --SOS--, --CH--CH--, --OCH.sub.2--, --CH.sub.2O--,
--CH.dbd.CH--, --C.ident.C-- or a single bond; k.sup.2 is an
integer. having a value of 0 or 1; and t.sup.2 and t.sup.3 are
integers, each independently having a value of 0 or 1; with the
proviso that oxygen atoms are not linked one to another.
9. A compound as claimed in claim 8, in which B.sup.1 and B.sup.2
each independently represent a group of formula (IV), wherein:
X.sup.2 to X.sup.3 each independently represent --O--, --CO--,
--COO--, --OCO--, --C.ident.C--, or a single bond, especially
--O--, --COO--, --OCO-- or a single bond; and Sp.sup.2 represents a
C.sub.1-20 straight-chain alkylene group, especially ethylene,
propylene, butylene, pentylene, hexylene, heptylene, octylene,
nonylene, decylene, undecylene or dodecylene.
10. A compound as claimed in any preceding claim, in which at least
one of MG.sup.1 and MG.sup.2 represents a mesogenic group
comprising at least two optionally-substituted aromatic or
non-aromatic carbocyclic or heterocyclic ring systems.
11. A compound as claimed in any preceding claim, in which one or
more of MG.sup.1 and MG.sup.2 represents a mesogenic group
comprising 1 to 4 aromatic or non-aromatic carbocyclic or
heterocyclic ring systems and optionally up to 3 bridging
groups.
12. A compound as claimed in claim 11, in which MG.sup.1 and
MG.sup.2 are selected from the meanings of formulae (V):
C.sup.1-(Z.sup.1-C.sup.2).sub-
.a1-(Z.sup.2-C.sup.3).sub.a2-(Z.sup.3-C.sup.4).sub.a3 (V) in which:
C.sup.1 to C.sup.4 are in each case independently
optionally-substituted non-aromatic, aromatic, carbocyclic or
heterocyclic groups; Z.sup.1 to Z.sup.3 are independently from each
other --COO--, --OCO--, --CH.sub.2--CH.sub.2--, --OCH.sub.2--,
--CH.sub.2O--, --CH.dbd.CH--, --C.ident.C--, --CH.dbd.CH--COO--,
--OCO--CH.dbd.CH-- or a single bond; and a1, a2 and a3 are
independently integers 0 to 3, such that a1.div.a2+a3.ltoreq.3.
13. A compound as claimed in claim 12, in which C.sup.1 to C.sup.4
are selected from: 18with: L being --CH.sub.3, --COCH.sub.3,
--NO.sub.2, --CN, or halogen u1 being 0, 1, 2, 3, or 4, u2 being 0,
1, 2, or 3, and u3 being 0, 1, or 2.
14. A compound as claimed in claim 13, in which C.sup.1 to C.sup.4
are selected from optionally-substituted cyclohexyl or
cyclohexylene, phenyl or phenylene, naphthyl or naphthylene or
phenanthryl or phenanthrylene.
15. A compound as claimed in any preceding claim, in which A.sup.1
to A.sup.4 are identical.
16. A compound as claimed in any preceding claim, in which E.sup.1
and E.sup.2 are identical.
17. A-compound as claimed in any preceding claim, in which MG.sup.1
and MG.sup.2 are identical.
18. A compound as claimed in any preceding claim, in which CG is a
chiral croup having at least two chiral centres more preferably two
adjacent chiral centres.
19. A compound as claimed in any preceding claim, in which B.sup.1
and B.sup.2 are identical and both consisting of single bonds,
oxygen atoms or an optionally-substituted hydrocarbon group of 1 to
3-C atoms.
20. A liquid crystalline material, in the form of a liquid
crystalline mixture, (co)polymer, elastomer, polymer gel or polymer
network, comprising at least two components, at least one of which
is a chiral compound, characterised in that the chiral compound is
a compound of formula (I) as claimed in claim 1.
21. A liquid crystalline material, in the form of a cholesteric
mixture, or cholesteric polymer network, comprising at least two
components, at least one of which is a chiral compound,
characterised in that the chiral compound is a compound of formula
(I) as claimed in claim 1.
22. A cholesteric polymer network obtainable by copolymerisation of
an optically active polymerisable mesogenic mixture comprising: i)
at least one chiral or/and achiral nematic polymerisable mixture
chosen from chiral and achiral nematic materials; ii) at least one
chiral dopant of formula (I) as claimed in claim 1; iii) an
initiator; iv) optionally a non-mesogenic compound having at least
one polymerisable functional group, more optionally a diacrylate
compound; and v) optionally a stabiliser;
23. A chiral polymerisable cholesteric mixture, essentially
consisting of: i) 70 to 99% by weight of at least one achiral
polymerisable liquid crystal; ii) 0.1 to 30% by weight of a chiral
compound of formula I as claimed in claim 1; iii) 0.1 to 5% by
weight of a photoinitiator; and iv) 0 to 5% of a stabiliser.
24. A cholesteric film obtainable by the steps comprising ordering
a chiral polymerisable cholesteric mixture as claimed in claim 23
in the monomeric state and ill situ UV polymerisation of the
resulting ordered mixture.
25. Use of a compound as claimed in any one of claims 1 to 19 as a
dopant for liquid crystals.
26. Use of a compound as claimed in any one of claims 1 to 19, or a
liquid crystalline material as claimed in claim 20 or 21, for
manufacturing a polymeric cholesteric layer.
27. Use of a cholesteric polymer network as claimed in claim 22, a
chiral polymerisable cholesteric mixture as claimed in claim 23, or
a cholesteric film as claimed in claim 24, in optical components
such as colour filters, optical pass band filters and polarisers.
Description
[0001] This invention relates to optically active materials and
their use as doping agents for liquid crystals for a wide range of
applications including solid state cholesteric filters for
projection displays, circular polarisers, optical filters, etc.
[0002] The addition of an optically-active compound to a
non-optically-active liquid crystalline phase is one of procedures
used for the conversion of non-optically-active into
optically-active mesophases. The nematic phase, for example, is
converted to the cholesteric one when being doped with a small
amount of an optically-active substance. This conversion manifests
itself by the occurrence of an intermolecular helix which is
characterised by the so-called helical twisting power (HTP) given
in Equation 1: 1 H T P = p - 1 x x = 0 p - 1 x = i x i ( H T P ) i
( 1 )
[0003] HTP (.mu.m.sup.-1) helical twisting power for small
concentrations
[0004] p(.mu.m) pitch of induced helix, + for (P)-helix, - for
(M)-helix
[0005] x mole fraction of the dopant
[0006] l sum over all optically-active conformers of the dopant
[0007] x.sub.i mole fraction of conformer i
[0008] Said HTP is in fact a measure for the efficiency of a given
dopant and is determined by the Cano method with solutions of the
dopant in the host mesophase. Since the optically-active guest and
the non-optically-active host compounds are not necessarily
compatible at the molecular scale, their binary solution is
frequently characterised by undesirable changes of the thermotropic
sequence of the initial host liquid crystalline material, like for
example a depression of the clearing point. Those changes could in
turn have negative effects on the phase properties of the host,
such as a decrease of the birefringence etc. Therefore, an
optically-active dopant is sought so that with very small
concentrations of this latter, large values of HTP could be
induced.
[0009] As such efficient optically-active dopants there are the
binaphthol derivatives described in GB-A-2 298 202. However
optically-active binaphthol derivatives may undergo partial
racemisation when being heated. Besides, their preparation is
expensive because it includes asymmetric resolution of binaphthol
racemate as a crucial reaction step.
[0010] Other classes of optically active dopants which are of
easier chemical access than binaphthol derivatives are those
described in U.S. Pat. No. 5,780,629, which are consisting of
compounds having at least one divalent or polyvalent chiral group
and at least one mesogenic group. Based on this molecular
architecture, in which the chiral group is present at peripheral
position of the mesogenic cores, we have prepared some chiral
dimesogenic derivatives. Nevertheless, their use as doping agents
for liquid crystals has only provided mixtures with a relatively
small HTP. However, we have now discovered that a further class of
compounds, including within its scope compounds that exhibit a
chiral group at lateral position is of at least two rod-like shaped
organic residues, is efficient for producing a large HTP. Besides,
their synthesis is trivial and inexpensive since they are obtained
in few reaction steps starting from commercially available
optically active residues.
[0011] Thus, the invention provides chiral "sandwich" derivatives
of formula I: 1
[0012] in which
[0013] A.sup.1 to A.sup.4 each independently represent hydrogen; an
optionally-substituted methyl group; or an optionally-substituted
hydrocarbon group of 2 to 80 C-atoms, in which one or more C-atoms
may be replaced by a heteroatom, in such a way that oxygen atoms
are not linked to one another;
[0014] E.sup.1 and E.sup.2 each independently represent hydrogen;
an optionally-substituted methyl group; or an
optionally-substituted hydrocarbon group of 2 to 80 C-atoms, in
which one or more C-atoms may be replaced by a heteroatom, in such
a way that oxygen atoms are not linked to one another;
[0015] B.sup.1 and B.sup.2 each independently represent a single
bond, an oxygen atom or an optionally-substituted hydrocarbon group
of 1 to 80 C-atoms, in which one or more C-atoms may be replaced by
a heteroatom, in such a way that oxygen atoms are not linked to one
another;
[0016] MG.sup.1 and MG.sup.2 each independently represent an
optionally-substituted aromatic or non-aromatic carbocyclic or
heterocyclic rings system, with 1 to 80 C-atoms;
[0017] CG is a divalent or polyvalent chiral croup derived, in
particular, from sugars; from optically active biaryls such as
optionally substituted binaphthyl or optionally substituted
biphenyl; or from bifunctional or polyfunctional compounds such as
optically active alcohols, glycols or amino acids; and
[0018] n1 and n2 are each independently 1 or 2, where "n1=2" (or
"n2=2") indicates the presence of two separate linkages via the
groups B.sup.1 (or the groups B.sup.2) between the groups MG.sup.1
and CG (or CG and MG.sup.2);
[0019] and in which further the substructures
A.sup.1-MG.sup.1-A.sup.2 and A.sup.3-MG.sup.2-A.sup.4 each have a
longitudinal axis and are linked lateral to the said longitudinal
axis to B.sup.1 and B.sup.2, respectively.
[0020] One possibility to form a longitudinal axis in the
substructures A.sup.1-MG.sup.1-A.sup.2 and A.sup.3-MG.sup.2-A.sup.4
are compounds where two or more rings or a fused ring system are
present in MG.sup.1 or MG.sup.2. Another possibility are compounds
where at least one of A.sup.1 or A.sup.2 and A.sup.3 or A.sup.4 is
different from hydrogen.
[0021] The compounds of the present invention are efficient for
producing a large HTP.
[0022] Their synthesis is trivial and inexpensive since they are
obtained in few reaction steps starting from commercially available
optically active residues.
[0023] They are compatible with liquid-crystalline compounds or
liquid-crystalline mixtures (no significant change of the clearing
temperatures when used as dopants in a liquid-crystalline
matrix).
[0024] They induce a large supercooling effect at the
liquid-crystalline state when used as dopants in liquid-crystalline
matrix hence avoiding crystallisation problems during the
manufacture of cholesteric films.
[0025] They may be used as doping agents for liquid crystals for a
wide range of applications including solid state cholesteric
filters for projection displays, circular polarisers, optical
filters, etc.
[0026] Preferred compounds of the present invention are those
belonging to formula (I), in which:
n1=n2=1.
[0027] Preferably at least one of A.sup.1 to A.sup.4, E.sup.1 and
E.sup.2 includes a polymerisable group, and each independently may
be selected from formula (II):
P-(Sp.sup.1).sub.k1-(X').sub.t1- (II)
[0028] wherein:
[0029] P is hydrogen or a polymerisable group selected from groups
comprising CH.sub.2.dbd.CW--, CH.sub.2.dbd.W--O--,
CH.sub.2.dbd.CW--COO--, CH.sub.2.dbd.C(Ph)--COO--,
CH.sub.2.dbd.CH--COO--Ph--, CH.sub.2.dbd.CW--CO--NH--,
CH.sub.2.dbd.C(Ph)--CONH--, CH.sub.2.dbd.C(COOR')--CH.sub.2--COO--,
CH.sub.2.dbd.CH--O--, CH.sub.2.dbd.CH--OOC--, (Ph)--CH.dbd.CH--,
CH.sub.3--C.dbd.N--(CH.sub.2).sub.m3--, HO--, HS--,
HO--(CH.sub.2).sub.m3--, HS--(CH.sub.2).sub.m3--,
HO(CH.sub.2).sub.m3COO-- -, HS(CH.sub.2).sub.m3COO--, HWN--,
HOC(O)--, CH.sub.2.dbd.CH--Ph--(O).sub- .m4. 2
[0030] wherein:
[0031] W represents H, F, Cl, Br or I or a C.sub.1-5 alkyl
group;
[0032] m3 is an integer having a value of from 1 to 9;
[0033] m4 is an integer having a value of 0 or 1,
[0034] R' represents a C.sub.1-5 alkyl group; and
[0035] R" represents a C.sub.1-5 alkyl group, methoxy, cyano, F,
Cl, Br or I;
[0036] Sp.sup.1 represents an optionally-substituted C.sub.1-20
alkylene group, in which one or more C-atoms may be replaced by a
heteroatom;
[0037] k.sup.1 is an integer having a value of from 0 to 4;
[0038] X.sup.1 represents --O--, --S--, --NH--, N(CH.sub.3)--,
--CH(OH)--, --CO--, --CH(CO)--, --SO--, --CH.sub.2(SO)--,
--SO.sub.2--, --CH.sub.2(SO.sub.2)--, --COO--, --OCO--, --OCO--O--,
--S--CO--, --CO--S--, --SOO--, --OSO--, --SOS--,
--CH.sub.2--CH.sub.2--, --OCH.sub.2--, --CH.sub.2O--,
--CH.dbd.CH--, or --C.ident.C--; and
[0039] t.sup.1 is an integer having a value of 0 or 1.
[0040] In relation to the residue of formula (II), the term Ph is
to be understood as denoting phenylene and (Ph) as denoting
phenyl.
[0041] The C.sub.1-20 alkylene group Sp.sup.1 may comprise branched
or straight chain alkylene groups and may be unsubstituted, mono-
or polysubstituted by F, Cl, Br, I or CN. Alternatively or in
addition one or more of CH.sub.2 groups present in the hydrocarbon
chain may be replaced, independently, by one or more groups
selected from --O--, --S--, --NH--, N(CH.sub.3)--, --CH(OH)--,
--CO--, --CH.sub.2(CO)--, --SO--, --CH(SO)--, --SO.sub.2--,
--CH.sub.2(SO.sub.2)--, --COO--, --OCO--, --OCO--O--, --S--CO--,
--CO--S--, --SOO--, --OSO--, --SOS--, --C.ident.C--,
--(CF.sub.2)-.sub.r, --(CD.sub.2).sub.s-- or
C(W.sup.1).dbd.C(W.sup.2)--, with the proviso that no two oxygen
atoms are directly linked to each other. W.sup.1 and W.sup.2 each
represent, independently, H, H--(CH.sub.2).sub.q1-- or Cl. The
integers r, s and q1 each independently represent a number of
between 1 and 15.
[0042] More preferably, A.sup.1 to A.sup.4 and E.sup.1 to E.sup.2
each independently represent a group of formula (III):
P.sup.2-Sp.sup.5-X.sup.4- (III)
[0043] wherein:
[0044] P2 represents hydrogen, CH.dbd.CW.sup.5-- or
CH.sub.2.dbd.CW.sup.5--(CO).sub.v2O--, 3
[0045] wherein:
[0046] W.sup.5 represents H, CH.sub.3, F, Cl, Br or I; and
[0047] v2 is 0 or 1,
[0048] R' represents a C.sub.1-5 alkyl group; and
[0049] R" represents a C.sub.1-5 alkyl group, methoxy, cyano, F,
Cl, Br or I;
[0050] Sp.sup.5 represents a C.sub.1-20 straight-chain alkylene
group, especially ethylene, propylene, butylene, pentylene,
hexylene, heptylene, octylene, nonylene, decylene, undecylene, or
dodecylene; and
[0051] X.sup.4 represents --O--, --CO--, --COO--, --OCO--,
--C.ident.C--, or a single bond, especially --O--, --COO--, --OCO--
or single bond.
[0052] One or more of A.sup.1 to A.sup.4 and E.sup.1 to E.sup.2 may
also represent a C.sub.1-C.sub.20-alkyl, C.sub.1-C.sub.20-alkoxy,
C.sub.1-C.sub.20-alkoxycarbonyl, C.sub.1-C.sub.20-alkylcarbonyl or
C.sub.1-C.sub.20-alkylcarbonyloxy group, for example methyl, ethyl,
propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl,
dodecyl, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy,
hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy, undecyloxy,
dodecyloxy, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl,
butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl,
octyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl,
undecyloxycarbonyl, dodecyloxycarbonyl, acetyl, propionyl, butyryl,
valeryl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl,
undecanoyl, dodecanoyl, terdecanoyl, acetoxy, propionyloxy,
butyryloxy, valeryloxy, hexanoyloxy, heptanoyloxy, octanoyloxy,
nonanoyloxy, decanoyloxy, undecanoyloxy, dodecanoyloxy,
terdecanoyloxy and the like.
[0053] In a second preferred embodiment of the present invention
each or either of the groups B.sup.1 and/or B.sup.2 comprises a
group of formula (IV):
(X.sup.2).sub.t2-(Sp.sup.2).sub.k2-(X.sup.3).sub.t3 (IV)
[0054] wherein:
[0055] Sp.sup.2 represents a C.sub.1-20 alkylene group;
[0056] X.sup.2 and X.sup.3 each independently represent --O--,
--S--, --NH--, N(CH.sub.3)--, --CH(OH)--, --CO--, --CH.sub.2(CO)--,
--SO--, --CH.sub.2(SO)--, --SO.sub.2--, --CH.sub.2(SO.sub.2)--,
--COO--, --OCO--, --OCO--O--, --S--CO--, --CO--S--, --SOO--,
--OSO--, --SOS--, --CH.sub.2--CH.sub.2--, --OCH.sub.2--,
--CH.sub.2O--, --CH.dbd.CH--, --C.ident.C-- or a single bond;
[0057] k.sup.2 is an integer, having a value of 0 or 1; and
[0058] t.sup.2 and t.sup.3 are integers, each independently having
a value of 0 or 1;
[0059] with the proviso that oxygen atoms are not linked one to
another.
[0060] Preferably B.sup.1 and B.sup.2 each independently represent
a group of formula (IV), wherein:
[0061] X.sup.2 to X.sup.3 each independently represent --O--,
--CO--, --COO--, --OCO--, --C.ident.C--, or a single bond,
especially --O--, --COO--, --OCO-- or a single bond; and
[0062] Sp.sup.2 represents a C.sub.1-20 straight-chain alkylene
group, especially ethylene. propylene, butylene, pentylene,
hexylene, heptylene, octylene, nonylene. decylene, undecylene or
dodecylene.
[0063] Especially preferred compounds are those in which B.sup.1
and B.sup.2 each independently represent a group of formula (IV)
and A.sup.1 to A.sup.4 and E.sup.1 to E.sup.2 each independently
represent a group of formula (III).
[0064] The invention is particularly useful when the groups of
MG.sup.1 and MG.sup.2 have a mesogenic architecture so that
compounds of formula (I) are able to be compatible with a host
liquid-crystalline single compound or mixture. Thus preferably at
least one of MG.sup.1 and MG.sup.2 represents a mesogenic group
comprising at least two optionally-substituted aromatic or
non-aromatic carbocyclic or heterocyclic ring systems.
[0065] Preferably one or more of MG.sup.1 and MG.sup.2 represents a
mesogenic group comprising 1 to 4 aromatic or non-aromatic
carbocyclic or heterocyclic ring systems and optionally up to 3
bridging groups. These are more preferably selected from the
meanings of formulae (V):
C.sup.1-(Z.sup.1-C.sup.2).sub.a1-(Z.sup.2-C.sup.3).sub.a2-(Z.sup.3-C.sup.4-
).sub.a2 (V)
[0066] in which:
[0067] C.sup.1 to C.sup.4 are in each case independently
optionally-substituted non-aromatic, aromatic, carbocyclic or
heterocyclic groups;
[0068] Z.sup.1 to Z.sup.3 are independently from each other
--COO--, --OCO--, --CH.sub.2--CH.sub.2--, --OCH.sub.2--,
--CH.sub.2O--, --CH.dbd.CH--, --C.ident.C--, --CH.dbd.CH--COO--,
--OCO--CH.dbd.CH-- or a single bond; and
[0069] a1, a2 and a3 are independently integers 0 to 3, such that
a1+a2+a3.ltoreq.3.
[0070] Especially preferred are those in which C.sup.1 to C.sup.4
are selected from: 4
[0071] with:
[0072] L being --CH.sub.3, --COCH.sub.3, --NO.sub.2, --CN, or
halogen
[0073] u1 being 0, 1, 2, 3, or 4,
[0074] u2 being 0, 1, 2, or 3, and
[0075] u3 being 0, 1, or 2.
[0076] More especially preferred are those in which C.sup.1 to
C.sup.4 are selected from optionally-substituted cyclohexyl or
cyclohexylene, phenyl or phenylene, naphthyl or naphthylene or
phenanthryl or phenanthrylene.
[0077] For ease of synthesis, the molecules of formula (I) may
possess some symmetrical aspects. These include the following
possibilities:
[0078] n1=n2=1;
[0079] A.sup.1 to A.sup.4 are identical;
[0080] E.sup.1 and E.sup.2 are identical;
[0081] MG.sup.1 and MG.sup.2 are identical;
[0082] CG is a chiral group having at least two chiral centres more
preferably two adjacent chiral centres; or
[0083] B.sup.1 and B.sup.2 are identical and both consisting of
single bonds, oxygen atoms or an optionally-substituted hydrocarbon
group of 1 to 3-C atoms.
[0084] Other aspects of the present invention are
[0085] a) a liquid crystalline material, especially in the form of
a liquid crystalline mixture, (co)polymer, elastomer, polymer gel
or polymer network, comprising at least two components, at least
one of which is a chiral compound, characterised in that the chiral
compound is a sandwich derivative of formula (I);
[0086] b) a liquid crystalline material, especially in the form of
a cholesteric mixture, or cholesteric polymer network, comprising
at least two components, at least one of which is a chiral
compound, characterised in that the chiral compound is a sandwich
derivative of formula (I);
[0087] c) a cholesteric polymer network obtainable by
copolymerisation of an optically active polymerisable mesogenic
mixture comprising:
[0088] i) at least one chiral or/and achiral nematic polymerisable
mixture chosen from the already reported broad range of chiral and
achiral nematic materials, for example as in Adv. Mater. 5, 107
(1993), Mol. Cryst. Liq. Cryst. 307, 111 (1997), J. Mat. Chem. 5,
2047 (1995) or in patent publications U.S. Pat. No. 5,593,617; U.S.
Pat. No. 5,567,349; GB-A-2297556; GB-A-22999333; DE-A-19504294;
[0089] EP-A-0606940; EP-A-0643 121 and EP-A-0606939, optionally
selected from EP-A-0606940; EP-A-0643121 and EP-A-0606939;
[0090] ii) at least one chiral dopant of formula (I);
[0091] iii) an initiator;
[0092] iv) optionally a non-mesogenic compound having at least one
polymerisable functional group, more optionally a diacrylate
compound; and
[0093] v) optionally a stabiliser;
[0094] d) chiral polymerisable cholesteric mixtures, essentially
consisting of:
[0095] i) 70 to 99%, preferably 85 to 95% by weight of at least one
achiral polymerisable liquid crystal;
[0096] ii) 0.1 to 30%, preferably 1 to 15% by weight of a chiral
compound of formula I;
[0097] iii) 0.1 to 5%, preferably 0.2 to 2% by weight of a
photoinitiator; and
[0098] iv) 0 to 5%, preferably 0.1 to 1% of a stabiliser; and
[0099] e) a cholesteric film obtainable by the steps comprising
ordering the above mixture in the monomeric state and iii situ UV
polymerisation of the resulting ordered mixture.
[0100] The invention also includes:
[0101] a) the use of the compounds as dopants for liquid
crystals;
[0102] b) the use of the compounds or liquid crystalline materials
for manufacturing a polymeric cholesteric layer; and
[0103] c) the use of the cholesteric polymer network, chiral
polymerisable cholesteric mixtures, or cholesteric film, in optical
components such as optical filters and polarisers, and especially
colour filters, optical pass band filters, solid state cholesteric
filters for projection displays and circular polarisers.
[0104] The compounds of the invention may be readily prepared using
methods that are well known to the person skilled in the art, such
as those documented in Houben-Weyl, Methoden der Organischen
Chemie, Thieme-Verlag, Stuttgart. The compounds may for example be
made according to the following reaction schemes: 5 6 7
[0105] EDC: N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide
hydrochloride, DMAP: N,N-Dimethylaminopyridine; DMF:
N,N-Dimethylformamide
[0106] According to the synthetic ways drawn in Schemes i-3 typical
examples representing polymerisable chiral "sandwich" derivatives
shown in the following list of compounds are prepared. This list
is, however, to be understood only as illustrative without limiting
the scope of the present invention: 8
EXAMPLE 1
[0107] Diisopropyl
L-2,3-bis{2,5-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-
benzoyloxy}-succinate 9
[0108] A solution of mesyl chloride (4.23 g, 36.94 mmol) in 10 ml
of dry THF was added dropwise under argon over a period of 15
minutes to a cooled (-25.degree. C.) solution of
4-(6-acryloyloxyhexyloxy)benzoic acid and triethylamine (20 ml) in
80 ml of dry THF. The reaction mixture was then stirred for 60 min
at -25.degree. C., treated with a solution of
2,5-dihydroxybenzaldehyde (2.3 g, 16.65 mmol) in 60 ml of dry THF
containing 195 mg of DMAP and further stirred at -25.degree. C. for
2h. The reaction mixture was then allowed to warm to room
temperature and stirring was continued overnight. The reaction
mixture was then poured into 120 ml of saturated NaHCO.sub.3 and
extracted with 2.times.200 ml of ether. The combined organic
extracts were washed with 3N HCl (200 ml) and semi-saturated NaCl
solution (2.times.100 ml), dried over MASO.sub.4, filtered and
dried to give a slightly yellow pasty material. This was purified
by flash chromatography over a short silica column
(CH.sub.2Cl.sub.2/Et.sub.2O : 19.5/0.5) to give a white residue
(9.25 g) which was dissolved in CH.sub.2Cl.sub.2 (25 ml) then
recrystallised from ethanol (250 ml) to give pure
2,5-di-[4-(6-acryloyloxy-hexyloxy)benzoylox- y]benzaldehyde as a
white crystalline material. Yield 8.5 g.
[0109] b) 2,5-Di-[4-(6-acryloxyhexyloxy)benzoyloxy]benzoic Acid
10
[0110] Jones oxidant (CrO.sub.3/H.sub.2SO.sub.4/H.sub.2O) (48 ml)
was added to a ice-cooled solution of
2,5-di-[4-(6-acryloyloxyhexyloxy)benzoy- loxy]benzaldehyde (8.24 g,
12 mmol) in acetone (300 ml) in a dropwise fashion over a period of
30 min. The reaction mixture was stirred overnight at room
temperature. The resulting green-orange mixture was filtered off to
leave a green precipitate that was washed with 600 ml of ether. The
combined organic solutions were washed with water until the orange
coloration disappeared (6.times.250 ml). The colourless organic
solution obtained was washed with saturated NaCl solution
(2.times.300 ml), dried over MgSO.sub.4 and filtered. Removal of
the solvent gave pure
2,5-di-[4-(6-acryloyloxyhexyloxy)benzoyloxy]benzoic acid as a white
crystalline material. Yield 8.5 g.
[0111] c) Diisopropyl
L-2,3-bis-{2,5-bis-[4-(6-acryloyloxyhexyloxy)benzoyl-
oxy]benzoyloxy}succinate
[0112] A solution of mesyl chloride (1.10 ml) in 5 ml of dry THF is
dropwise added to a solution of
2',5'-bis-[2,5-di-(4-(6-acryloyloxyhexylo- xy)benzoyloxy)]benzoic
acid (10 g) and triethylamine (19.8 nil) in 125 ml of dry THF,
cooled at -25.degree. C. and maintained and under argon atmosphere.
After complete addition (15 min), the reaction mixture is further
stirred for 120 min at -25.degree. C. then treated with a solution
of diisopropyl L-tartrate (1.35 g) in 20 ml of dry THF containing
695 mg, of DMAP and the reaction mixture is further stirred at
-25.degree. C. for 2 h. The temperature is then allowed to reach
room temperature and stirring is continued overnight. The reaction
mixture is filtered over Celite and evaporated to dryness to afford
a slightly beige pasty material. This is then flash chromatographed
over a silica column affording pure diisopropyl
L-2,3-bis-{2,5-bis-[4-(6-acryloyloxyhexyloxy)b-
enzoyloxy]benzoyloxy} succinate [the "L" indicating the formal
derivation of the compound from diisopropyl L-tartrate] as a
transparent oily material which becomes pasty upon standing.
[0113] Yield: 5.0 g.
EXAMPLE 2
[0114] Diisopropyl
D-2,3-bis-{2,5-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy-
]benzoyloxy-succinate 11
[0115] Following the procedure described in Example 1 (C), the
reaction was performed with 10 g of
2',5'-bis-[2,5-di-(4-(6-acryloyloxyhexyloxy)be- nzoyloxy)]benzoic
acid, 1.10 ml of mesyl chloride , 19.8 ml of triethylamine, 1.5 g
of diisopropyl L-tartrate and 695 mg of DMAP to afford, after flash
chromatography over a silica column, pure diisopropyl
D-2,3-bis-{2,5-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]benzoyloxysuccina-
te [the "D" indicating the formal derivation of the compound from
diisopropyl D-tartrate] as a transparent oily material which
becomes pasty upon standing.
[0116] Yield: 6.3 g.
EXAMPLE 3
[0117]
O,O-Di-{2,5-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]benzoyl}-1,4,3-
,6-dianhydro-D-mannitol 12
[0118] Following the procedure described in Example 1 (C), the
reaction was performed with 1.5 g of
2',5'-bis-[2,5-di-(4-(6-acryloyloxyhexyloxy)b- enzoyloxy)]benzoic
acid, 0.17 ml of mesyl chloride, 3 ml of triethylamine, 0.14 g of
1,4,3,6-dianhydro-D-mannitol and 61 mg of DMAP in 50 ml of THF to
afford, after flash chromatography over a silica column, pure
O,O-di-{2,5-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]benzoyl}--1,4,3,6-di-
anhydro-D-mannitol as white crystalline material.
[0119] Yield: 0.28 g.
EXAMPLE 4
[0120] A mixture is formulated consisting of
[0121] 1% by weight of 13
[0122] and
[0123] 99% by weight of 14
[0124] This mixture forms a cholesteric phase with a pitch of p=4
.mu.m.
* * * * *